状态相关非饱和土力学理论及应用  

State-dependent theory for unsaturated soil and its applications

作　　者：吴宏伟[1] 周超 张帅[1] 郭浩文 张琪 倪钧钧 赵仲辉 陈锐 NG Charles WangWai;ZHOU Chao;ZHANG Shuai;GUO HaoWen;ZHANG Qi;NI JunJun;CHIU Abraham ChungFai;CHEN Rui(Department of Civil and Environmental Engineering,The Hong Kong University of Science and Technology,Hong Kong 999077,China;Department of Civil and Environmental Engineering,The Hong Kong Polytechnic University,Hong Kong 999077,China;Department of Underground Engineering,School of Transportation,Southeast University,Nanjing 211189,China;Department of Civil and Environmental Engineering,College of Engineering,Shantou University,Shantou 515063,China;School of Civil and Environmental Engineering,Harbin Institute of Technology,Shenzhen 518055,China)

机构地区：[1]香港科技大学土木及环境工程学系,中国香港999077 [2]香港理工大学土木及环境工程学系,中国香港999077 [3]东南大学交通学院地下工程系,南京211189 [4]汕头大学工学院土木与环境工程系,汕头515063 [5]哈尔滨工业大学(深圳)土木与环境工程学院,深圳518055

出　　处：《中国科学：技术科学》2023年第10期1728-1746,共19页Scientia Sinica(Technologica)

基　　金：香港政府研究资助局卓越学科领域计划(编号:AoE/E-603/18);国家自然科学基金(批准号:U20A20320)资助项目。

摘　　要：陆表土体绝大多数处于非饱和状态,它是所有建筑物与边坡的承载体,也是植物生长的根基.在全球气候变化引发的强降雨等极端天气事件以及日益增强的人类工程活动影响下,陆表非饱和土极易发生塑性变形、失稳滑动或生态退化等灾病害.据联合国减灾办公室统计,近50年的非饱和土边坡滑动灾害造成全球1000多万人死亡.传统非饱和土力学理论难以解决气候变化与工程活动作用下非饱和土中普遍存在的渗流-变形-强度耦合问题,也无法考虑非饱和土与植物间的相互作用.通过长期对非饱和土力学的系统研究,笔者研究团队发现了吸力和应力状态耦合影响非饱和土渗流-变形-强度的规律,建立了状态相关非饱和土本构理论;推导了植被非饱和土的渗流与稳定性计算方法,为非饱和土生态护坡提供了科学依据,进而研发了生态型三层土质覆盖系统,解决了传统方法容易失稳和老化问题.新型覆盖系统已成功应用于深圳最大的生活垃圾填埋场,被在编国标推荐使用.Unsaturated soils are ubiquitous on the surface of the Earth and play an important role in construction engineering and vegetation growth.Their properties are governed not only by the stress state but also by the moisture content(i.e.,suction),and are influenced by many factors such as engineering activities,climate change and vegetation.Seepage,deformation and instability in unsaturated soils have led to many disasters(e.g.,slope failures,excessive embankment settlement and ecological degradation)and pose a threat to sustainable development,especially under climate change.According to the International Disaster Database,unsaturated soil slope failures have been responsible for over 10 million deaths over the past 50 years.The classical theory of unsaturated soil mechanics is inadequate to accurately analyse seepage-deformation-stability coupled problems under the effects of climate change and engineering activities.It also does not consider the hydromechanical interaction between unsaturated soil and vegetation.To redress these lacunae in the applicability of the classical theory,the research team led by the first author of this paper conducted extensive research on unsaturated soil mechanics and its applications.The team revealed the state-dependent hydromechanical coupling behaviour of unsaturated soils and developed a novel state-dependent elasto-plastic constitutive framework.The new framework was used to formulate design guidelines to improve the design of slopes and pavements.The research team also developed a theoretical method for calculating the seepage and stability of vegetated unsaturated soils,establishing a solid scientific basis for investigations of unsaturated bioengineered slopes.The team also developed a novel sustainable cover system using construction waste that eliminates the need for a geomembrane.This new system was successfully applied at the Xiaping landfill site,which is the largest domestic waste landfill in Shenzhen,and has now been adopted by China’s national standard“Technical

关 键 词：非饱和土 状态相关 持水特性 小应变剪切模量 剪胀(缩) 植被土 水力加固 滑坡 土质覆盖系统 

分 类 号：TU43[建筑科学—岩土工程]